The present invention relates to a tape for semiconductor package and a method of cutting thereof.
Tape automated bonding (TAB) was introduced as a replacement for a conventional wire bonding technology. TAB is now used for a semiconductor package such as a tape carrier package (TCP) and a chip on film (COF) in liquid crystal displays, watches, cameras, memory cards, calculators, personal computers and other electronic devices. TAB provides a high-density interconnect from IC chips to substrate, allowing full automation of the bonding of one end of the tape wiring pattern to the IC chips and the other end of the tape wiring pattern to the substrate.
FIG. 5 is a schematic view showing a conventional (TAB/COF) tape with a lead pattern on a base, in which a lead spacing A is 27 μm, a distance B between the central lines of two adjacent leads 1 is 58 μm. A narrow wire 2 provided at the end of each lead 1 is uniformly formed at the central line of the correspondingly lead 1 so as to provide a central narrow wire pattern as show in FIG. 5. The production process shows that such central narrow wire pattern is prone to result in some technical defects when cutting the narrow wires, such as reducing life of a cutting tool and producing burrs at cut edges of the cutted narrow wires and the like.
When the conventional TAB/COF tapes are sequentially cut with a cutting tool, the cutting positions of the cutting tool for the narrow wires of each tape are constant in the continuous operations, and thereby these positions of the blade of the cutting tool are subject to repeating wear. The life of the cutting tool is only about 100,000 times of cutting. If the cutting tool cannot be replaced in time, the worn cutting tool will generate burrs at the cut edges. When a burr is larger than 15 μm in length, it may cause a short between two adjacent leads, resulting in two-bright line (two-line) defect.